Describing the move as "very, very unusual", Judge Richard Bond said that Clarke's old age and health meant the court will only hear evidence between 9.30am and 1.30pm.

Judge Bond added: "I have made that decision because the interests of justice decree that this defendant, like any defendant who is tried in a Crown Court, must be able to follow the evidence and must be in position to call evidence himself if that time arises.

He has got be able to follow this trial. So let's all be patient. It's only fairJudge Richard Bond

"I am sure that you will all understand why we have to accommodate Mr Clarke in this particular way.

"At the forefront of my mind I have his welfare. He has got be able to follow this trial. So let's all be patient. It's only fair."

Clarke, who is thought to be the oldest defendant to stand trial in a British court, is alleged to have committed the offences against two girls and a boy, including one as young as seven, between 1974 and 1983.

Before the case was opened at Birmingham Crown Court on Monday, Judge Bond informed the jury there would be occasions when Clarke left the hearing without permission for personal reasons.

Explaining that Clarke would also be assisted by an intermediary helping him to follow the proceedings, the judge told the panel: "There will be occasions during the trial when the defendant will speak, possibly quite loudly, to the intermediary, who is likely to speak quite loudly back to him.

"The reason for this is that Mr Clarke, not surprisingly at the age of 101, is hard of hearing. I invite, in fact I direct you, to ignore any such communications between Mr Clarke and the intermediary - or with his barrister.

"The reason for that is that those communications are normally private, but you are bound to hear them in this case for obvious reasons."

The former lorry driver leaned on a walking stick for support while sitting on the back row of the barristers' benches as the Crown's case against him was opened.

Clarke, of Erdington, Birmingham, denies 17 charges of indecent assault, 12 offences of indecency with a child and two attempted serious sexual offences.

At the start of the pensioner's trial, prosecutor Miranda Moore QC told jurors two of Clarke's alleged victims walked into a police station in August last year to make a complaint against him.

Miss Moore told the jury: "What they were to tell the police was a history of a catalogue of serious sexual abuse."

Alleging that some of the abuse took place in a garage at Clarke's then home in Erdington, Miss Moore told the jury panel of six men and six women: "All three victims talk about being in a garden shed or workshop.

He agreed some of the things you are going to hear about did in fact happen. His first words were 'Who has complained?Miranda Moore QC

"Probably today you would call it a 'man shed' or a 'man cave'."

People from all over the area would take things to Clarke - who was regarded locally as something of a handyman - for him to repair, Miss Moore added.

When Clarke was questioned by police last December, the court heard, he made "limited admissions" to officers.

Miss Moore said: "The defendant was interviewed by the police in this case. He agreed some of the things you are going to hear about did in fact happen. His first words were 'Who has complained?"'

Concluding her opening speech, Miss Moore stressed age is no barrier to a defendant being tried "as long as the trial is fair and the evidence is clear".

Clarke took off his white flat cap after entering court, but did not take off his coat during the proceedings. The trial continues on Tuesday.